Hello,
using piwigo since many years (actual over 50k pictures and 550 albums), but (I think) with the update to 2.9.5 I have an issue and I do not know why.

    Piwigo 2.9.5
    Betriebssystem: WINNT
    PHP: 7.0.5 (Info anzeigen) [2019-05-01 13:23:50]
    MySQL: 5.5.5-10.3.12-MariaDB [2019-05-01 13:23:50]
    Grafikbibliothek: External ImageMagick 6.9.3-8
    Using physical albums, not virtual


Have imported new pictures via synchronization. Some pictures were horizontal and some vertical.
Unfortunately all thumbnails for the vertical pictures were created horizontal !.

Any hint is welcome.

Have deactivated all plugins and tested several themes. Problem still exist.

Regards
kuzco